Can browser send a command to a servlet?

[Michael Kann]

The following lesson shows how to send a command from a revlet to the browser. 

http://lessons.runrev.com/spaces/lessons/buckets/784/lessons/8173-How-do-I-communicate-with-the-browser-from-a-plugin-

Might anyone know how to go the other way: click a button on the browser and have it do something in the revlet. The goal, of course, is to make the roundtrip.

Thanks in advance,

Mike